Also IMO rolling backwards is completely unnecessary for this type of bike because it's so easy to pivot in place.
Wow, that is utterly not my experience. Getting around in tight places with lots of people (subway tunnels, escalators, buses, TRAIN AISLES, and ELEVATORS) pivoting in place is usually absurd.
In what world are fold-in-half bikes balanceable on their wheels without arm strength? I think you're mistaking something.